i have some questions related to VFD ( variable frequency drive ) used for controlling the speed of induction motor .I would be thankful for your answers . My questions are following .
1) Can VFD provide smooth control of induction motor speed ?
2) How does it avoids high in rush starting currents of the induction motors ?
3) What is the function of using a microcontroller connected with the inverter ? Is it used for generating pwm ? if yes than how generated pwm controls the inverter's output ?
4) VVVF ( variable voltage variable frequency ) and VFD( variable frequency drive ) are they two terms used for a single concept or not ?
Kindly explain it to me based on concepts of power electronics and electronics engineering . thanks
VFD , it usually has a ramp control ,with min and max freq output,with many other menu's and there a control panel (could be removable) , and a special cable to communicate with it through a laptop . you may send me your VFD model and the manufacture to help you more
hope it helps
look at http://youtu.be/zbm_83YTkO4